Dental root-canal point



L. O. CARD DENTAL ROOT CANAL POINT Oct. 9 1923,

Filed Aug. '7, 1922 I Lea/z; 0.62mi 6 53 M? 7 Q .98

Patented Oct. 9, 1923.

DENTAL ROOT-CANAL roman Application filed August 7, 1922. Serial No.580,024.

To all whom it may concern:

Be it known that I, LEWIS O. CARD, a citizen of the United States,residing at Somerville, in the county of Middlesex and State ofMassachusetts, have invented new and useful Improvements in Dental Root-Canal Points, of which the following is a specification.

This invention relates to a device known as a root point used bydentists in applying an antiseptic to the walls of a canal in a toothroot, after the canal has been opened up and cleaned by a tool adaptedfor that purpose, preparatory to filling, the point being usually leftin the tooth for a considerable period, while the antiseptic is acting.

It is the common practice to employ as a root point, a slender wisp orplug of absorbent fibrous material, such as absorbent cotton, the plugbeing formed for insertion in a canal. Owing, however, to the fact thatsuch plug is limp, or has no inherent stiffness, it is a difiicultmatter to insert it to the closed end of the canal, and cause theapplication of the antiseptic to the inner end and the entire wall ofthe canal.

My invention is embodied in a root point which overcomes theabove-mentioned and other objections to the ordinary root point.

Of the accompanying drawings forming a part of this specification,-

Figure 1 is a side view of a root point embodying the invention, ofapproximately the actual size.

Figure 2 is a side View considerably enlarged, a portion of theabsorbent plug being shown in section.

Figure 3 is a sectional view of a tooth, and a side view of my improvedroot point inserted in a canal thereof.

Figure 4 shows a portion of the wire member of my improved root point,on a larger scale than in Figures 2 and 3.

The same reference characters indicate the same parts in all of thefigures.

The root point shown by the drawings comprises a compressible plug- 15,of fibrous absorbent material, such as absorbent cotton, and a core ofattenuated flexible wire 12, within and adhering to the plug, the pointbeing adapted to be inserted in and conform to the curvature of a rootcanal 13. The outer end of the wire core is bent to form a hook-engagingportion 14, adapted to be engaged by the usual exploring hook used bydentists.

The gage of the wire and the diameter of the plug are such that when thepoint is inserted in the canal, the plug is slightly compressed by, andcontacts with, the entire wall, and with the closed end of the canal, sothat a liquid antiseptic carried by theplug is applied to all portionsof said wall and to said inner end.

The core so stifii'ens the core that the latter reaches the closed endof the canal when the point is fully inserted. The fibrous material maybe applied by twisting it around the wire core to form a plug ofsuitable diameter, slip-preventing means being provided for preventingthe plug from being longitudinally displaced on the core when the pointis being inserted and removed. To this end the major portion of the wirecore may be roughened 0r corrugated, as by forming thereon minute teethor barbs 18, shown much enlarged by Figure 4, the fibrous material beingwound with sufiicient closeness to cause it to engage the corrugatedportion.

The length of the core is such that its hook-engaging portion 14 isadapted to occupy a cavity in the body of the tooth, without projectingtherefrom, as shown by Figure 3, so that the point may remainindefinitely in the tooth while the antiseptic is acting, withoutinterference with the function of the tooth, the portion 14 beingcovered by a temporary filling.

My improved point is not adapted to per form the usual operation ofopening up and cleaning the canal, this operation being usuallyperformed by a broach which, while sufficiently flexible to conform tothe curvature of the canal, has sufiiciently inherent stiffness toenable it to perform its function, and is necessarily elongated toproject from the tooth in which it is inserted.

It will be seen, therefore, that the point embodying my invention isintended and adapted only to follow a tool such as a broach, and applyan antiseptic to all porq tions of a canal which has been opened up andcleaned.

- In inserting the canal point, the end portion 14 is firmly grasped bya pair of dental cotton pliers and pushed into the canal of the tooth.In removing the canal point a hooked dental explorer is used, byengaging the hook of the explorer with the portion 14 of the canalpoint. When the fibrous material 15 swells, as it will when wet, the

removal of the point would be difficult, if pushed into'and' Withdrawnfrom the'canal, the portion 14 Were not provided. said core having ahook-engaging portion at I claim: its outer end adapted to occupy acavity in A device for treating the Walls of a canal the body of; thetoot-h Without projecting 5 of a tooth root composed of a compressibletherefrom, so that the device Will not inter- 1 plug of absorbentmaterial, formed to exfere With the use of the tooth While a root tendthroughout the length of a root canal in canal thereof is being treatedby it. a tooth, and a core of attenuated flexible In testimony whereof Ihave affixed my Wire, Within and adhering to the plug, signature.

10 whereby the plug is adapted to be readily LEWIS O. CARD.

